Pearse Doherty, Sinn Fein's finance spokesman, said: "The fact that only in September they were supposed to have published final figures shows the ongoing contempt the banks for the Central Bank's process and for the victims."

The party is to propose new laws next week to allow for class action suits.

Mr Doherty added: "Public and political pressure must now be focused on Ulster Bank whose timetable is pitifully slow and on Permanent TSB who have returned customer to a rate well above what their contract entitles them to.

"I am convinced that the testimony of victims and the work of the Finance Committee have brought about a real momentum that was sorely lacking from Government or the Central Bank."

"We have been provided with no information as to why these customers have been excluded up to now," he said.

Mr McGrath added: "Many people, including myself, have lost all faith in the approach of the banks to dealing with this tracker scandal.

"The numbers keep changing, the banks are dragging their feet and there is no sense that they are close to getting to the bottom of the problem."

Earlier: Another 6,000 Bank of Ireland customers were wrongly denied a lower cost tracker mortgage, the bank has said.

It said the cost of compensating all those identified to date will be up to 200 million euro.

Francesca McDonagh, Bank of Ireland chief executive, said she was offering affected customers an unreserved apology for "the financial loss and anxiety this has caused them and their families".

"This now gives us a clear picture of the number of impacted customers," she said.

"The compensation process is commencing, and our priority is to ensure that all impacted customers are compensated as quickly as possible.

"I believe that the way in which we address this issue will define the customer-centric culture we aspire to at Bank of Ireland and this is why I have made resolving this issue my personal priority since joining the bank."

Bank of Ireland previously said it had identified 4,300 customers, 3,700 who were on a higher interest rate under a tracker borrowing contract and 600 who had been denied a tracker mortgage.

The announcement of 6,000 additional customers being denied trackers takes the number of mortgage holders who were done out of low-cost interest rates by a number of banks to about 28,000.

Bank of Ireland initially said it was setting 25m euro aside to cover the compensation bill.

After identifying thousands more customers who were impacted it will set aside another 150 to 175m euro.

Ulster Bank expected its bill for compensation and redress to run to 175m; AIB 190 million euro; and KBC up to 60 million euro.

All the banks have offered apologies.

About 100 homeowners and investors across a number of banks lost properties in the scandal.

Bank of Ireland said the first 4,300 customers identified can expect to be compensated by the end of this year.

It said the other 6,000 newly identified borrowers will be returned to their correct tracker rate as soon as possible, if they are still with the bank, and that compensation will be paid as soon as possible, with the first offers being made before the end of the year.